I realise the concept is difficult, but let me show you this and it should satisfy you that everything we are seeing is connected.

This chart is a cumulative count of all quakes in the region since 01 Jan 2009 - sorry about the masses of white space I accidentally put in 2008 and
I have no data until 2009. Even so you can see fore-shocks building very slowly up to the 8.8 and then away she goes and has not come back down
yet.

According to the news hundreds of people have fled to higher ground in the feat that the tremor may trigger a tsunami. Chilean Navy officials have not
issued a warning. Still citizens there are leary of any quake on or so close to shore. The quake occurred at 20:20:16 UTC time according to the
official USGS notifier in the Araugania region some 370 miles Southwest of Santiago. The quake was at a relatively shallow depth of only 10.5 miles
deep, but so far no significant damage or any injuries have been reported. According to the USGS’s shakemaps, the quake was of moderate felt
intensity reaching out to about 100 km from the epicenter.

I appreciate the graph and your comments. I understand the concept. I was aware that the number of quakes there had run well above the average since
the big one of last year.

That's not a problem. The problem I have is what I set out in my previous post, namely (in summary) that the concept of aftershocks as some kind of
assumed cause-and-effect relationship is way too simplistic. We are using statistics to support an assumption that may not even be wholy valid.

I'll put it another way before I get out of here for the night.

As I see it, the term "aftershock" implies that the later events in a given region are either caused by the effects of an earlier, larger event in
the same region, or are directly attributable to those effects. That's where I have a problem -- which wasn't a problem for me until about an hour
ago when you led my mind in that direction.

The aftershock concept doesn't allow enough for the fact that energy is coming into the local seismic system from outside. It's way too assumptive
and I think we need to study it more, because we are being led to use it as the answer to quakes when it may not always be so.

That's all I'm trying to say.

Okay I will now find that whisky. Good night, all. Let's hope nothing else happens. This sort of quake "action" is not what I like to see, as it
means many people in that part of Chile will now at the very least have some more sleepless nights -- and some might even have been killed.

I don't think this is an "aftershock" of the 8.8 as such, but there may be a "triggering" effect.

Geologists did a bit of research on earthquakes in the Fiordland area of NZ which is also a subduction zone like Chile, and they think that each
quake triggers the next one, and it can span 10-30 years.
In the New Zealand case they were getting bigger each time, from 1938's 6.9 Charles Sound, 1989's 6.4 in Doubtful Sound, 2003 Secretary Is. 7.3Mw,
through to the 2009 Dusky Sound 7.6 Mw, with a bunch of 6's along the way for good measure.

In Chiles case it seems to be in reverse, back from the 1960 Mag 9.6 [Catalog of worldwide earthquakes with Ms 7.0> 1900-1989 Pacheco and Sykes
(1992)]

I'm with you on this one Muzzy - I don't see these two 7's as aftershocks - IMO. At All!!! We had aftershocks of a main event that has gone of
since the main event simmering back down to near backround levels (got that line from our friends at yvo ;-)) - as the graphs show -steady but surely.
Then two 7's back to back in the same general area, but not right on top or really near each other, after the quietness - no - I think something
else is about snap or major re-adjustment is about to happen.

- large aftershocks can occur months or years after a large mainshock... while there's generally a
tailing off in mag/frequency, having very large aftershocks after a period of relative calm isn't unusual, particularly for large quakes like their
8.8.

I'll go with this answer for now but I don't really get the Gutenberg-Richter relation rule:

Aftershocks are also interesting because they're fairly well behaved—meaning that they have a detectable pattern, unlike all other quakes. The
definition that scientists use for an aftershock is any seismic event occurring within one rupture-zone length of a main shock and within the time it
takes for seismicity to fall off to what it was before the main shock. This body of quakes fits three mathematical rules, more or less. The first is
the Gutenberg-Richter relation, which says that as you go down one magnitude unit in size, aftershocks increase in number by about ten times. The
second is called Bath's law, which says that the largest aftershock is, on average, 1.2 magnitude units smaller than the main shock. And finally,
Omori's law states that aftershock frequency decreases by roughly the reciprocal of time after the main shock. These numbers differ a bit in
different active regions depending on their geology, but they're close enough for government work as the saying goes.

Anyway, as quakes in Utah sometimes seem to get deleted after a short time I'll just note that I have screen shots of the data page (being the page
you've quoted from), as well the World map, USA and Nth America maps, and the Local Region map. So if by chance this quake does a disappearing act
then I'll upload those images here and post them on the thread.

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